Fertility doctors don’t give standing ovations very often. But when a team of Swedish doctors announced at a recent conference the first-ever birth of a baby to a woman who had a womb transplant, it nearly blew the doors off the room.

Lawmakers in the United Kingdom voted recently to allow fertility clinics to use mitochondrial manipulation technology (MMT) to enable women with mutations in mitochondrial genes to have genetically healthy children . But the US Food and Drug Administration (FDA) is being much more conservative and is awaiting results of further preclinical research before allowing clinical trials to begin. The technology is of concern because it manipulates the germline, something many countries prohibit.

U.S. fertility rates have reached another record low, at 62.5 births per 1,000 women of childbearing age, according to the most recent government figures. To some, this is cause for hand-wringing, as concerns arise that low fertility will spell problems for the nation’s economy; while others, concerned about limited natural resources, may look positively on the decline.

When it comes to parents, it seems that three or even four is no longer a crowd. At least, that’s the conclusion one might draw from the case of Sheena and Tiara Yates, a married lesbian couple in New Jersey. They’ve had their parenting expectations upended—twice—by the sperm donors of their two kids. Both men agreed, in writing, to provide their raw materials and to leave the parenting to the women. But then they decided that, after all, they’d like to have some role in the lives of their biological children, so they applied for visitation rights. As of now, the bio dads are winning. Their case is just the latest reminder of how perilous and confusing assisted reproduction cases can become.